Gilead Sciences Finalizes Agreement with Tibotec Pharmaceuticals to Develop and Commercialize a Single-Tablet Regimen of Prezista® with Emtriva®, GS 7340 and Cobicistat

FOSTER CITY, Calif.--(BUSINESS WIRE)--Nov 15, 2011 - Gilead
Sciences, Inc. (Nasdaq: GILD) today announced that it has entered
into a license agreement with Tibotec Pharmaceuticals for the
development and commercialization of a single-tablet regimen
combining Prezista® (darunavir) with Gilead's
Emtriva® (emtricitabine); its investigational agent
GS 7340, a novel prodrug of tenofovir; and cobicistat, a
pharmacoenhancer.

“We are pleased to once again be partnering with Tibotec
to advance and simplify HIV treatment for patients,” said
Norbert Bischofberger, PhD, Executive Vice President, Research and
Development and Chief Scientific Officer, Gilead Sciences.
“This is the first time we are developing a protease
inhibitor-containing single-tablet regimen, and we're able to do
that based on the small milligram size of GS 7340, which is less
than one tenth of the amount of the 300 mg of tenofovir disoproxil
fumarate contained in Viread and Truvada.”

Gilead will be responsible for the formulation, manufacturing,
registration and, subject to regulatory approval, distribution
and commercialization of the single-tablet regimen worldwide.
Tibotec will have the right to co-detail the single-tablet regimen
in certain major markets.

Gilead first entered into a collaboration with Tibotec in July
2009 for the development and commercialization of a single-tablet
regimen combining Gilead's Truvada®
(emtricitabine/tenofovir disoproxil fumarate) and Tibotec's
Edurant® (rilpivirine). The product was approved
under the trade name Complera®
(emtricitabine/rilpivirine/tenofovir disoproxil fumarate) in the
United States in August 2011.

On June 28, 2011, Gilead announced a licensing agreement with
Tibotec for the development of a fixed-dose combination containing
Prezista and cobicistat, which was contingent upon the signing of
the agreement to develop the Prezista, Emtriva, GS 7340 and
cobicistat single-tablet regimen. Both agreements have now been
finalized. Subject to regulatory approval, Tibotec will be
responsible for the formulation, manufacturing, registration,
distribution and commercialization of the Prezista and
cobicistat fixed-dose combination worldwide.

About Cobicistat

Gilead is evaluating cobicistat in three separate pivotal Phase
3 studies, both as a stand-alone boosting agent for once-daily
atazanavir, as well as part of the all Gilead fixed-dose
single-tablet Quad regimen of elvitegravir, cobicistat and Truvada
for the treatment of HIV infection.

About GS 7340

GS 7340, Gilead's investigational anti-HIV agent, is a novel
prodrug of tenofovir, the active agent in the company's HIV drug
Viread® (tenofovir disoproxil fumarate). Phase 2a
dose-ranging studies have identified a dose that is ten times lower
than Viread and provides greater antiviral efficacy. Gilead expects
to initiate a Phase 2 study of GS 7340 early next year.

Cobicistat, GS 7340 and the Quad are investigational products
and their safety and efficacy have not yet been established.

About Gilead Sciences

Gilead Sciences is a biopharmaceutical company that discovers,
develops and commercializes innovative therapeutics in areas of
unmet medical need. The company's mission is to advance the care of
patients suffering from life-threatening diseases worldwide.
Headquartered in Foster City, California, Gilead has operations in
North America, Europe and Asia Pacific.

This press release includes forward-looking statements, within
the meaning of the Private Securities Litigation Reform Act of
1995, that are subject to risks, uncertainties and other factors,
including risks related to whether ongoing clinical trials for
cobicistat and GS 7340 will be successful and Gilead's ability to
formulate cobicistat and GS 7340 with other agents, including
darunavir. In addition, safety and efficacy data from clinical
trials may not warrant further development of cobicistat, GS 7340
or the single-tablet regimen. Further, the regulatory authorities
may not approve cobicistat and GS 7340 as stand-alone products or
in any combination product, and marketing approval, if granted, may
have significant limitations on its use. As a result, cobicistat,
GS 7340 and the single-tablet regimen may never be successfully
commercialized. The parties may make a strategic decision to
discontinue development of the combination product if, for example,
Gilead is unable to successfully formulate the single-tablet
regimen or the market for the product fails to materialize as
expected. These risks, uncertainties and other factors could cause
actual results to differ materially from those referred to in the
forward-looking statements. These and other risks are described in
detail in Gilead's Quarterly Report on Form 10-Q for the quarter
ended September 30, 2011, as filed with the U.S. Securities and
Exchange Commission. All forward-looking statements are based on
information currently available to Gilead, and Gilead assumes no
obligation to update any such forward-looking statements.

Drugs.com provides accurate and independent information on more than 24,000 prescription drugs, over-the-counter medicines and natural products. This material is provided for educational purposes only and is not intended for medical advice, diagnosis or treatment.